Submarine rock placing traveler

ABSTRACT

A ballast placing system for underwater pipe lines makes use of a traveler vehicle operating on the ocean floor to place aggregate material at the sides of a pipe line as ballast. The vehicle has a frame including side members which straddle the pipe line and a central structure located above the pipe line interconnecting the side members. Adjacent the aft end of each side member is a hydraulic activated Caterpillar Drive unit for moving the vehicle in a forward direction and forward of the Caterpillar Drive unit is a supporting sled and a guide structure for aligning the vehicle relative to the pipe line. At the top of the central structure is a hopper from which extends a downwardly directed chute which divides into two branch chutes, one located on each side of the pipe. A screed device at the lower end of each branch chute gages the amount of aggregate which is deposited by each respective branch chute. Caterpillar treads of the drive unit are actuated to move the vehicle progressively forward as promptly as aggregate deposited at the sides of the pipe line reaches a predetermined level. The hopper is supplied through a telescoping feed chute from a tender anchored at the surface, above and in alignment with the pipe line. The tender is pulled forward on anchor cables at a pace matching travel of the vehicle on the ocean floor and a crane on the tender lifts aggregate from a supply barge and discharges it into the feed chute. Hydraulic circuits for operating parts of the system stem from a control panel carried by the tender and are supplied by a pump on the tender.

United Staes Patent [451 Sept. 5, 1972 Keating [54] SUBMARINE ROCK PLACING TRAVELER [72] Inventor: James J. Keating, Richmond, Calif.

[73] Assignee: Peter Kiewit Sons Company, Omaha, Nebr.

[22] Filed: Sept. 3, 1971 21 Appl. No.: 177,656

[52] US. Cl. ..61/63, 61/46, 61/72.1, 61/72.3, 222/176 [51] Int. Cl ..E02d 15/10, E02d 27/46 [58] Field of Search ..61/72.3, 72.1, 72.2, 72.5, 61/72.6, 72.7, 46, 63; 222/176, 177, 178, 478

[56] References Cited UNITED STATES PATENTS 2,435,758 2/1948 Snyder .222/176 X 2,652,695 9/1953 Paulson ..61/63 3,267,682 8/1966 Robley ..61/72.3

Primary ExaminerJacob Shapiro Att0rneyBeehler, Arnat & Jagger [5 7] ABSTRACT A ballast placing system for underwater pipe lines makes use of a traveler vehicle operating on the ocean floor to place aggregate material at the sides of a pipe line as ballast. The vehicle has a frame including side members which straddle the pipe line and a central structure located above the pipe line interconnecting the side members. Adjacent the aft end of each side member is a hydraulic activated Caterpillar Drive unit for moving the vehicle in a forward direction and forward of the Caterpillar Drive unit is a supporting sled and a guide structure for aligning the vehicle relative to the pipe line. At the top of the central structure is a hopper from which extends a downwardly directed chute which divides into two branch chutes, one located on each side of the pipe,

A screed device at the lower end of each branch chute gages the amount of aggregate which is deposited by each respective branch chute. Caterpillar treads of the drive unit are actuated to move the vehicle progressively forward as promptly as aggregate deposited at the sides of the pipe line reaches a predetermined level.

The hopper is supplied through a telescoping feed chute from a tender anchored at the surface, above and in alignment with the pipe line. The tender is pulled forward on anchor cables at a pace matching travel of the vehicle on the ocean floor and a crane on the tender lifts aggregate from a supply barge and discharges it into the feed chute.

Hydraulic circuits for operating parts of the system stem from a control panel carried by the tender and are supplied by a pump on the tender.

17 Claims, 14 Drawing Figures PATENTEDsEP 5:912

SHEET 2 UF 5 mm mm SUBMARINE RGCK PLACING TVIELER frequently being laid from a trestle where the water depth is not great but wherein as the depth increases pipe lengths are laid by a pipe laying frame supported on the ocean bottom, sometimes submerged, and sometimes supported above the surface on long legs which rest on the ocean bottom. Pipe lines are sometimes laid one pipe length at a time but where conditions permit, many pipe lengths may be joined together at the surface and then laid in multiple units on the ocean floor, divers usually being employed to make up the joint before pipe lengths are released from the laying apparatus.

Although conditions on the ocean floor at depths of 50 to 200 or more feet are relatively calm and undisturbed, sufficient to count on the pipe line being undisturbed for a moderate period of time, it is necessary to firmly anchor the pipe line in place before the operation is completed by use of what is termed ballast. As that term is used herein ballast means gravel or crushed rock and may vary in size from 1% to 2 inch stones for pipe lines of small diameter up to 4 inch diameter average size stones for pipe of large diameter. The ballast is usually dumped on or near the pipe line in expectation that enough will be deposited close to the pipe line to hold it in position. When this practice is depended on much of it is wasted and its effect as ballast is entirely lost.

Since it is advisable to place ballast to a height more or less equal to the center line of the pipe namely, half way between the bottom and the top, appreciably more ballast is needed for a pipe of large diameter than a pipe of small diameter. Further still, the top level of the ballast should be maintained with a great degree of precision. Though specifications may provide for some difference in profile to suit a particular set of conditions the top level is customarily at or near the spring line of the pipe, namely, at about half the distance between the bottom and the top of the pipe. The top of the profile should have a level area outwardly from the pipe and for pipe of 120 inches diameter the level area should be about two feet wide. Ballast should extend laterally outwardly to a point either at or beyond the angle of repose.

It is therefore among the objects of the invention to provide a new and improved system for placing ballast along a submarine pipe line which is certain in its performance, which is economical of time and which avoids waste of ballast material.

Another object of the invention is to provide a new and improved system for placing ballast along a submarine pipe line wherein machines can be depended upon to deposit ballast to an optimum level, evenly and dependably upon both sides of the pipe line at a progressive rate which can follow along behind the pipe laying operation before there has been opportunity for the pipe line once laid to be disturbed.

Still another object of the invention is to provide a new and improved submarine rock placing traveler which is capable of accurately following the pipe line without at the same time disturbing the pipe line, which is self propelled, and which can function without need for being constantly supervised by a diver while dependably placing ballast progressively and simultaneously on both sides of the pipe line with a reasonable degree of rapidity.

Still another object of the invention is to provide a new and improved submarine rock placing traveler which is equipped to effectively screed the top level of the ballast as it is being placed so that only the necessary amount of ballast will be deposited, thereby being economical of material while at the same time, operating with great assurance in having adequate ballast at all times irrespective of the rough or even character of the ocean floor.

Still another object of the invention is to provide a new and improved submarine rock placing traveler which is of such construction that it can be easily altered in order to effectively place ballast at the sides of pipe of virtually any expected diameter.

Further included among the objects of the invention is to provide a new and improved submarine rock placing traveler wherein the weight of the apparatus is supported by a traveling vehicle, supporting portions of which are spaced far enough laterally away from the pipe line to assure that the pipe line will not be disturbed during the ballast placing operation and which is also constructed on such fashion that virtually equal amounts of ballast will be placed simultaneously on opposite sides of the pipe line so that there will be assurance that the deposited aggregate itself will not disturb the alignment of the pipe line once it has been established.

With these and other objects in view, the invention consists in the construction, arrangement, and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the claims and illustrated in the accompanying drawings.

In the drawings:

FIG. l is a side elevational view of the overall system in operation showing the rock placing traveler operating on the ocean floor and it being supplied from a tender floating above it on the ocean surface.

FIG. 2 is a transverse view taken on the line 22 of FIG. 1.

FIG. 3 is an end elevational view of the traveler taken on the line 33 of FIG. ll.

FIG. 4 is a side elevational view of the traveler taken on the line 44 of FIG. 3.

FIG. 5 is an opposite end elevational view taken on the line 55 of FIG. 4.

FIG. 6 is a fragmentary plan view of one of the Caterpillar Drive units with frame portions partially broken away taken on the line 66 of FIG. 4.

FIG. 7 is a fragmentary side elevational view of the Caterpillar Drive unit taken on the line 7-7 of FIG. 6.

FIG. 8 is a fragmentary sectional view taken on the circular line 8 of FIG. 6.

FIG. 9 is a fragmentary cross-sectional view taken on the line 9-9 of FIG. 8.

FIG. is a fragmentary elevational view of one of the screeds, partially broken away, taken on the line 1010 of FIG. 3.

FIG. '11 is a fragmentary elevational view of one of the screeds, partially broken away, taken at 90 with respect to the view of FIG. 10 and on line ll-ll of FIG. 10.

FIG. 12 is a fragmentary cross-sectional view on the line 1212 of FIG. 11.

FIG. 13 is a fragmentary end elevational view showing the underwater traveler adjusted to a pipe diameter smaller than that shown in FIG. 3.

FIG. 14 is a cross-sectional view of the traveler in the adjustment of FIG. 13, at a location comparable to the view of FIG. 5.

In an embodiment of the invention chosen for the purpose of illustration, there is shown a rock placing submarine traveler indicated generally by the reference character 10 operating on the floor or bottom 1 1 of the ocean and being supplied by a floating tender 12 anchored in place on the ocean surface 13 by means of fore and aft anchor cables 14 and 15. Piping 16 is employed for passing aggregate to be used as ballast, from the tender 12 to the traveler 10. A crane 17 on the deck of the tender is provided for lifting aggregate from a supply barge 18 and passing it to a carriage 19 at the top of the piping 16. A control conduit 20 extends from the tender 12 to the traveler 10. The equipment is made use of in placing ballast 21 to anchor a pipe line 22 in position.

The traveler 10 consists principally of a self propelled vehicle which straddles the pipe line 22 and which is capable of receiving aggregate from the tender and placing it simultaneously on both sides of the pipe line. The vehicle consists of a frame which has side members which for purposes of description are designated broadly by reference characters 25 and 26, the side members thus identified being in a position straddling the pipe line and supporting above them a central structure 27. The side members and central structure consist in the main of substantially conventional structural columns, cross-beams, and sway braclng.

Extending forward from the side member 25, as shown in FIG. 4 for example, is a lateral frame element 28. A similar element 29 is located on the opposite side. The frame element 28 is supported at its forward end by a sled 30 which is attached to a laterally extending arm 31 by connecting struts 32. On the opposite side a comparable sled 33 is connected to an arm 34 by connecting struts 35. The sleds 30 and 33 are adapted to slide on the floor or bottom 11 of the ocean and support the forward end of the respective lateral frame elemeat 28 or 29 as the case may be. These lateral frame elements are relatively long and, being used for steering or guiding the traveler, are provided respectively with guides 36 and 37 which engage opposite sides of the pipe line 22. Structural I beams 38 and 39 anchored respectively to the lateral frame elements 28 and 29 support the guides 36 and 37 and transfer the guiding affect of the guides to the lateral frame elements and hence to the traveler 10. To take advantage of the greatest leverage effect the guides 36 and 37 are preferably located near the forward end of the lateral frame elements 28 and 29 as the case may be. They also each span several pipe lengths for better guiding dependability.

To move the traveler progressively forward along the pipe line 22 use is made of self-propelled Caterpillar Drive units indicated generally by the reference characters 40 and 41. Since these drive units are substantially the same except for right and left hand operation details of the drive unit 40 only will be described.

As shown to good advantage in FIGS. 6, 7, 8, and 9 the Caterpillar Drive unit 40 employs fore and aft wheels 42 and 43 over which travels a caterpillar tread 44. The tread is made up of links 45 from which extends tlanges 46 which are adapted to dig into the floor 11 of the ocean to get additional traction. Side beams 48 support the wheels through axles 49, columns 50 being made use of for attaching the Caterpillar Drive unit to a horizontal plate 51 and then to a horizontal tubular member 52 of the side member 25.

A shield 55 extends throughout the length of the Caterpillar Drive unit to shield it from engagement with possible contact with rocks from the placement of the ballast 21.

For operation of the Caterpillar Drive unit 40 of the embodiment shown use is made of a pair of hydraulic rams and 61. In this embodiment of the invention a cylinder 62 of the ram 60 is connected to a structural element 63 at the top of the column 50, in a fore and aft position such that a piston rod 64 extends aft into engagement with a ratchet carriage 65. A similar piston rod 66 from the ram 61 is connected to a comparable ratchet carriage 67. The ratchet carriage slides fore and aft in a guideway or track 68, the guideway or track 68 being carried by the column 50 and a transverse square tubular beam 69 serving as a track support. A similar track support 70 is located forward of the track support 69. The ratchet carriage 67 is supported by a guideway or track 71 in a similar fashion. Slide shoe guides 72 and 73 on the ratchet carriage 65 overlie opposite sides of the links 45 to improve the guiding affect. It is contemplated that they may use other conventional hydraulic means or that on occasion an electric drive might be preferable.

To transfer motion from the piston rod 64 to the caterpillar tread 44 use is made of a pair of upper and lower grab arms 75 and 76 pivotally mounted upon the ratchet carriage 65 by means of a pin 77. A spring 78 biases the grab arm 75, counter clockwise as viewed in FIG. 8, until it engages a stop 79, the grab arm 76 being similarly biased by means of a spring 80. Both grab arms 75 and 76 are adapted to engage respective upper and lower ends of drive pins 81 which extend through each of the links 45 of the caterpillar tread 44, as shown in FIG. 9. Similar grab links are provided on the ratchet carriage 67 which are adapted to engage similar drive pins 82 on the opposite side of the caterpillar tread 44.

Operating simultaneously, the ratchet carriages 65 and 67 are driven aft by the respective piston rods 64 and 66 and the grab arms 75 and 76 yield as they ratchet past adjacent ends of the drive pins 81 and 82 until the carriages reach their aft-most positions. Action of the piston rods 64 and 66 is then reversed pulling the ratchet carriage of 65 and 67 forward. Meanwhile the grab arms 75 and 76 have been pulled by their respective springs to position adapted to engage the next adjacent drive pins 81 and 82. When power is applied to the piston rods 64, 66 in forward moving direction the upper reach of the caterpillar treat 44 is moved forwardly forcing the lower reach which is in contact with the ocean floor rearwardly and movement in this direction propels the vehicle forward along the pipe line. Clearly, this is an intermittent forward movement carried out as the ratchet carriages reciprocate, but the overall effect is a progressive movement at a speed sufficiently rapid for the operation which is taking place. Application of driving force is balanced on opposite sides of the caterpillar tread and the carriages are stabilized with relationship to each other by opposite acting engagement with the guideways of 68 and 71. Hydraulic action is supplied through the control conduit 20 when operation is needed, as called for by the screeding operation applied to the ballast 21.

Apparatus for deposit of the ballast 21 on the ocean floor 11 is shown to good advantage in FIGS. 3, 10, 11, and 12. For receiving aggregate to be used as ballast from the piping 16 there is provided a hopper 90 carried by the central structure 27 as shown in FIG. 3. A main chute 91 at the bottom of the hopper 90 divides into branch chutes 92 and 93 on respectively opposite sides of the pipe line 22. The branch chutes 92 and 93 terminate respectively in downwardly extending chute sections 94 and 95. At the lower end of the chute section 94 is a screed unit indicated generally by the reference character 96 and a similar screed unit 97 is provided at the outlet end of the other chute section 95. Except for left and right hand orientation, the screed units are the same and a description of only the screed unit 97 will be detailed. Extending downwardly from a horizontal end edge 98 of the chute section 95 is a sleeve 99, the sleeve 99 being bolted to the chute section 95 by means of bolts 100 and acting with it as a stationary unit. Surrounding the exterior of the lower end of the sleeve 99 is a wall structure forming a vertically reciprocating screed 101. The lower end of the screed 101 has a special form featuring a downwardly projecting wall portion 102. At the outside, is an edge 103 which extends obliquely upwardly and inwardly to a horizontal edge 104, the purpose of which is to provide a level portion 105 for the top of the ballast 21 and a slope 106, as shown in FIG. 3.

Guide bars 107, 108 on the inner faces of the screed 101 form vertical guideways to accommodate respective guide shoes 109 on the sleeve 99. The profile for the top of the ballast provided by the edges 103 and 104 is especially important to force the aggregate into proper position and prevent wasteful spilling of material.

For moving the screed 101 between maximum up and maximum down positions as indicated by the dimension a of FIG. there are provided hydraulic rams 110 and 111 comprising respectively cylinders 112 and 113, upper ends of which are pivotly secured to respective brackets 114 and 115, the brackets being anchored to the sleeve 99 by pivot pins 116. Hydraulic lines 117 and 118 supply the rams.

Extending downwardly from the cylinder 112 is a piston rod 119 which is attached to a bracket 120 extending upwardly from a square tubular section 121 at the lower end of the screed 101. Similarly, a piston rod 122 from the cylinder 113 engages a bracket 123 also attached to the square tubular section 121. Power supplied to the rams and 111 is by the mechanism just described made use of in changing the elevation of the lower edge portions of the screed 101 as operation requ1res.

For signalling the position of the screed 101 there is provided a sensor mounted at the outside end of an arm 131 which in turn is connected to the sleeve 99, as shown in FIG. 11. A sensing arm 132 pivotally connected to a shaft 133 of the sensor is provided with a slot 134 in which a piece 135 of an actuator arm 136 is adapted to engage. The actuator arm is anchored to a bracket 137 on the screed 101, the position of which can be adjusted upwardly or downwardly by relieving set screws 138. By operation of the sensing arm 132 in response to movement of the actuator arm 136 the position of the screed 121 is transmitted to the sensor and reported through an appropriate electric or hydraulic line through the control conduit 20 to a central control.

As heretofore described the aggregate is passed from the tender 12 downwardly through the piping 16 to the traveler on the ocean floor. Barges 18 loaded with aggregate in the form of crushed rock are able to tie up on one side of the tender as shown in FIG. 2 namely, the side opposite from which the carriage 19 is located. A loader 140 may be employed to fill a transfer hopper 141, or other appropriate means to enable the crane 17 to transfer aggregate from the barge 18 to the operation.

By having a tender 12 anchored in alignment with the pipe line, it is convenient to have the carriage 19 mounted so as to be located outboard directly over the pipe line 22. By having long anchor cables one anchorage of the tender serves to place ballast along the pipe line for a considerable distance, before the tender needs to be shifted to a new anchorage further along the pipe line. A control panel or console 143 is mounted on the tender at a location convenient with respect to the carriage 19. A suitable pump unit 142 supplying hydraulic liquid under pressure is also carried by the tender.

On the carriage 19 is a holding hopper 145 from the lower end of which extends an upper section 146 which is in a telescoping association with a lower section 147, together forming a supply chute. Variation in level of ocean floor is customarily not sufficiently great but what one setting of the upper and lower sections 146 and 147 with relation to each other, will accommodate the placing of ballast for a section of the pipe line 22 comparable to the length of the tender, before a change in the telescopic setting may be made necessary.

At the upper end of the central structure 27 of the submarine placing traveler 10, as shown in FIG. 2, there is provided a cage 148 having a relatively wide striker ring 149 and relatively narrower guide ring 150, the inside diameter of the guide ring being appreciably larger than the outside diameter of the lower section 147 of the supply chute to loosely accommodate it. Having the wide striker ring 149 comparably larger improves the ease with which the lower section 147 can be injected into it when readjustment becomes necessary. Moreover, by having the lower section 147 fit loosely in the cage some appreciable misalignment can be tolerated between the rock placing traveler exemplified by the vehicle and the location of the carriage on the tender above it. It will be understood that although alignment can be maintained with reasonable accuracy during calm water, changes in the condition of the surface 13 of the ocean as a result of wind and tide may be appreciable even though anchor cables hold firm. Changes in alignment may also occur as a result of irregularities in the ocean floor.

Additionally, by having what may be described as a tower section 151, extend relatively high above the hopper 90 the lower end 152 of the lower section 147 can move up and down a distance equal to the distance between the top of the hopper 90 and the narrow guide ring 150 of the cage without having the lower end 152 be sufficiently in misalignment but what aggregate flowing out of the supply chute will all be caught in the upper end of the hopper 90. A hopper extension 153 may be of further assistance in bringing the operating parts herein above described together in proper working relationship. As a further convenience there is provided a platform 154 extending laterally outwardly from the tower section 151 which can be used for accessory equipment such as a sonar hopper level indicator 155 and a profiler transducer 156.

When there is a change in the diameter of the pipe line 22 readjustment of the locations of the screed units becomes necessary. Such a change in location is illustrated in FIG. 13, and needs to be accompanied by a change in location of the guides 36 and 37, as shown in FIG. 14. Inasmuch as such changes occur infrequently, no more than two or three times in the laying of a pipe line of considerable extent, it is preferable to haul the entire rig out of water and rebuild the changes into the rig before it is again placed on the ocean floor.

The adjustment problem for relocation of the screed units 96 and 97 is substantially minimized by providing auxiliary sleeves 160 and 161 interposed between respective screed units 96 and 97 and the respective chute sections 94 and 95. Since, except for left and right hand orientation, the adjustment on both sides is the same, the description will be confined to installation of the auxiliary sleeve 161 only. The auxiliary sleeve 161 has a lower edge 162 extending at 90 degrees with respect to the longitudinal axis but is provided with an oblique upper edge 163. The angular disposition of the oblique upper edge is made such that, taking into consideration the overall length of the auxiliary sleeve 161, the sleeve 99, the screed 101, and the difference in location between the center of a pipe line 22 of smaller diameter than the pipe line 22, the outflow end of the screed 101 will be brought to a position immediately adjacent the pipe line 22' at a location substantially half way between the lower and upper sides, as shown in FIG. 13. For ease in applying and removing the auxiliary sleeve 161 to the assembly connections at its lower and upper edges 162 and 163 may be made by conventional bolted flanges, of the character suggested by the bolts 100 of FIGS. and

1 l in the arrangement there illustrated.

Although the horizontal disposition of the horizontal edge 104 and the oblique edge 103 of the-screed 101 may differ slightly from that described in connection with the adjustment for the pipe line 22 of the maximum diameter, the change in orientation will not be sufficient to interfere with a proper leveling of the top of the ballast and disposition of the slope at its sides. Moreover, the tilt of the screed 101 as shown in FIG. 13, is not too great but what the sensor can be depended upon for proper reporting of the screeding operation.

When a new and smaller pipe size for a pipe line such as 22' is encountered, the guides 36 and 37 must be relocated so that they are on a horizontal level at an elevation mid-way between the top and bottom of the smaller pipe line 22'. To accomplish this longer struts 157 and 158 may be employed for the lateral frame elements 28 and 29 and a longer strut 159 for the respective side members 25 and 26. By this construction that I beams 38 and 39 are relocated so that the elongated guides 36 and 37 which span and engage bell sections of a number of lengths of pipe are capable of keeping the vehicle in good alignment with respect to the smaller pipe line.

Although readjustment of the screeds has been described for only two different diameters of pipe line it will be appreciated that a pipe line of a still different diameter may be accommodated in similar fashion, whether the pipe line be larger or smaller than the pipe line 22'. To accommodate pipe lines of such other diameters it is necessary only to vary the length of the auxiliary sleeve 160, 161 and the angular disposition of the oblique upper edges 163.

For synchronizing the travel speed of the underwater traveler or vehicle with movement of the carriage 19 on the tender and the deposit of aggregate from the screed 101, the control panel 143 on the tender is made use of, inasmuch as such electric and hydraulic lines as are applied are carried between the tender 12 on the surface and the submarine rock placing traveler on the ocean floor. Such electric or hydraulic conduits communicate with each of the operating parts.

In operation the level of the screeds is determined with relation to the center line of the pipe line 22 and the screeds 101 are initially set at such a predetermined level. Because it is the profile established by the outlet end of the screed defined by the oblique end 103 and horizontal edge 104, setting this elevation is significant. The final precise setting may be accomplished by operation of the hydraulic rams 1 10 and 1 l 1. When the setting has reached the desired level this can be detected by the sensor 130 which is triggered by the position of the actuator arm 136 fastened to the screed 101.

It is important that a level of aggregate be retained in the hopper at all times in order to be certain that there will be no low spots in the placing of the ballast 21. Because of the position of the screed, there will be no over filling. To be certain of there being aggregate in the hopper 90, the sonar hopper level indicator located on the platform 154 is depended on and this information signalled to the control panel; The operator at the control panel actuates the Caterpillar Drive for the rock placing traveler 10 by keeping it moving as long as there remains rock in the hopper 90. When the sonar hopper level indicator indicates an absence of rock then the Caterpillar Drive is halted until rock has been deposited in the hopper.

The profiler transducer 156 also located on the platform 154 is made use of for the purpose of recording the true cross sectional shape of the ballast and the corresponding pipe progressively along the pipe line after the ballast has been deposited.

As the traveler 10 moves along the pipe it becomes necessary to shift the position of the carriage 19 even though appreciable angular disposition between the carriage 19 and the pipe line 16 can be allowed because of the gimbal connection 167 between the upper section 146 and the hopper 145. Some lag in movement of the tender can be permitted, relative to movement of the vehicle. Hence it is sufficient to move the tender by taking up on forward anchor cables at the bow and paying off on aft anchor cables 14 at the stern to move the tender along as the traveler progresses. When the limit has been reached for operation on the anchor cables operation is suspended until the anchors can be reset in order to be able to progressively move the tender along toward new locations.

Furthermore, it is possible to interconnect the pipe line 16 by means of the lower section 147 without the use of a diver, with the assistance of the profiler transducer to the extent that, knowing the location of the traveler and consequently the location of the cage 148 the pipe line can be lowered into the cage guided by the wide upper ring serving as a striker ring and ultimately the narrower lower end of the cage serving as a guide ring for guiding the lower end 152 of the section 147 into a proper location above the hopper 90. Looseness in the relationship between the guide ring 150 and the lower section 147 permits appreciable angular disposition of the pipe line relative to the hopper 90 without impairing the deposit of aggregate into the hopper.

When the apparatus is reset for a pipe line of different diameter, a comparable initial procedure is resorted to in order to set the elevation of the lower edge of the screeds 101 which, on such occasion, have been attached by interposition of the auxiliary sleeves 160 and 161.

Operated as described a precise amount of aggregate serving as ballast can be deposited and held in position closely adjacent the sides of the pipe line as well as being struck off to a precise level at the top, thereby to minimize loss or waste of aggregate which would otherwise occur as by mere random deposition of such aggregate along side of or on top of the pipe line.

Having described the invention, what is claimed as new in support of Letters Patent is:

1. In a submarine traveler for placing ballast around pipe lengths of a submarine pipe line a vehicle comprising a frame having side members adapted to straddle the pipe line and a central structure located above the side members and adapted to travel above the pipe line,

a Caterpillar Drive unit on each side member comprising a fore and aft moving tread and an actuator therefor,

a lateral frame element extending longitudinally away from the drive unit, a ground engaging support on each lateral frame element adapted to move with the frame element and spaced longitudinally from the drive unit, a steering guide means on said frame adapted to engage the pipe line and set the direction of travel of said vehicle,

an upwardly open hopper on the central structure having a main chute extending downwardly therefrom, a pair of branch chutes fed from said main chute and adapted to travel on respective opposite sides of the pipe line, a downwardly directed outflow part at the lower end of each branch chute, and means for supplying aggregate material to the hopper on a continuing schedule.

2. A submarine traveler as in claim 1 wherein there is a screed unit comprising a wall structure extending around the outflow part of each branch chute and slidable telescopingly with respect thereto;

3. A submarine traveler as in claim 2 wherein there is a sensor in communication respectively with the screed and chute adapted to indicate the position of the screed relative to the chute.

4. A submarine traveler as in claim 2 wherein the screed units on the branch chutes operate independently of each other.

5. A submarine traveler as in claim 2 wherein there is a hydraulic ram operatively connected respectively to each screed unit and the respective branch chute whereby to move the screed relative to the chute.

6. A submarine traveler as in claim 2 wherein the lower end of each screed unit has a side portion located on the laterally outward side which extends downwardly a greater distance than the opposite side portion whereby to direct ballast to a downwardly sloped configuration when in place.

7. A submarine traveler as in claim 1 wherein said steering guide means comprises a guide arm on each lateral frame element, each said guide arm extending inwardly at a level intermediate upper and lower sides of the pipe line whereby to direct the alignment of the vehicle with respect to the pipe line.

8. A submarine traveler as in claim 1 wherein said ground engaging support is a fore and aft extending sled adapted to engage the ocean floor at a location spaced laterally from the adjacent side of the pipe line.

9. A submarine traveler as in claim 1 wherein each Caterpillar Drive unit comprises a hydraulic ram on the lateral frame element and a drive connection between the hydraulic ram and the tread.

10. A submarine traveler as in claim 9 wherein the drive connection comprises projections on the tread extending outwardly therefrom and a ratchet, one of two relatively movable hydraulic ram members extending into driving engagement with said projections upon movement longitudinally of said one relatively movable hydraulic ram member whereby to drive the ground engaging portion of the tread in a direction generating forward movement of the vehicle.

1 1. A submarine traveler as in claim 10 wherein each projection lies on opposite faces of the tread and the ratchet comprises upper and lower grab arms engagable with projections in respective upper and lower faces of the tread and wherein there is a slide shoe supporting the grab arm and a guide-way in the side member of the frame in sliding relationship with the slide shoe whereby to stabilize the location of the grab arms during operation.

12. A submarine traveler as in claim 1 wherein there is a fore and aft extending shield plate located on the inner side of each caterpillar unit adapted to shield the caterpillar unit from ballast placed by the vehicle.

13. A submarine traveler as in claim 1 wherein there is a floating tender at the surface, a supply chute extending downwardly therefrom, an annular retainer surrounding the upper end of said hopper, a cage on the frame above said hopper and in substantially vertical alignment therewith, said cage having a relatively larger opening at the upper end and a relatively smaller opening at the lower end whereby to loosely receive the lower end of the supply chute.

14. A submarine traveler as in claim 13 wherein there is a carriage on the tender, and a holding hopper on the carriage, said supply chute being connected to and fed from said holding hopper.

15. A submarine traveler as in claim 1 wherein for each branch chute there is a sleeve, a screed comprising a wall structure telescopingly movably connected to said sleeve and an extension sleeve intermediate the sleeve and the branch chute, said extension sleeve having a length adapted to adjust the location of the outflow port relative to the diameter size of the pipe line.

16. A submarine traveler as in claim 15 wherein an end edge of the extension sleeve is at an acute angle relative to the longitudinal axis of the sleeve whereby to locate the outflow port nearer to the center line of the pipe line.

17. A submarine traveler as in claim 1 wherein there is a profile scanning device on the frame having a clear path of reference to the ballast after deposit'and the pipe line adjacent thereto for sensing the finished profile of the ballast relative to the pipe. 

1. In a submarine traveler for placing ballast around pipe lengths of a submarine pipe line a vehicle comprising a frame having side members adapted to straddle the pipe line and a central structure located above the side members and adapted to travel above the pipe line, a Caterpillar Drive unit on each side member comprising a fore and aft moving tread and an actuator therefor, a lateral frame element extending longitudinally away from the drive unit, a ground engaging support on each lateral frame element adapted to move with the frame element and spaced longitudinally from the drive unit, a steering guide means on said frame adapted to engage the pipe line and set the direction Of travel of said vehicle, an upwardly open hopper on the central structure having a main chute extending downwardly therefrom, a pair of branch chutes fed from said main chute and adapted to travel on respective opposite sides of the pipe line, a downwardly directed outflow part at the lower end of each branch chute, and means for supplying aggregate material to the hopper on a continuing schedule.
 2. A submarine traveler as in claim 1 wherein there is a screed unit comprising a wall structure extending around the outflow part of each branch chute and slidable telescopingly with respect thereto;
 3. A submarine traveler as in claim 2 wherein there is a sensor in communication respectively with the screed and chute adapted to indicate the position of the screed relative to the chute.
 4. A submarine traveler as in claim 2 wherein the screed units on the branch chutes operate independently of each other.
 5. A submarine traveler as in claim 2 wherein there is a hydraulic ram operatively connected respectively to each screed unit and the respective branch chute whereby to move the screed relative to the chute.
 6. A submarine traveler as in claim 2 wherein the lower end of each screed unit has a side portion located on the laterally outward side which extends downwardly a greater distance than the opposite side portion whereby to direct ballast to a downwardly sloped configuration when in place.
 7. A submarine traveler as in claim 1 wherein said steering guide means comprises a guide arm on each lateral frame element, each said guide arm extending inwardly at a level intermediate upper and lower sides of the pipe line whereby to direct the alignment of the vehicle with respect to the pipe line.
 8. A submarine traveler as in claim 1 wherein said ground engaging support is a fore and aft extending sled adapted to engage the ocean floor at a location spaced laterally from the adjacent side of the pipe line.
 9. A submarine traveler as in claim 1 wherein each Caterpillar Drive unit comprises a hydraulic ram on the lateral frame element and a drive connection between the hydraulic ram and the tread.
 10. A submarine traveler as in claim 9 wherein the drive connection comprises projections on the tread extending outwardly therefrom and a ratchet, one of two relatively movable hydraulic ram members extending into driving engagement with said projections upon movement longitudinally of said one relatively movable hydraulic ram member whereby to drive the ground engaging portion of the tread in a direction generating forward movement of the vehicle.
 11. A submarine traveler as in claim 10 wherein each projection lies on opposite faces of the tread and the ratchet comprises upper and lower grab arms engagable with projections in respective upper and lower faces of the tread and wherein there is a slide shoe supporting the grab arm and a guide-way in the side member of the frame in sliding relationship with the slide shoe whereby to stabilize the location of the grab arms during operation.
 12. A submarine traveler as in claim 1 wherein there is a fore and aft extending shield plate located on the inner side of each caterpillar unit adapted to shield the caterpillar unit from ballast placed by the vehicle.
 13. A submarine traveler as in claim 1 wherein there is a floating tender at the surface, a supply chute extending downwardly therefrom, an annular retainer surrounding the upper end of said hopper, a cage on the frame above said hopper and in substantially vertical alignment therewith, said cage having a relatively larger opening at the upper end and a relatively smaller opening at the lower end whereby to loosely receive the lower end of the supply chute.
 14. A submarine traveler as in claim 13 wherein there is a carriage on the tender, and a holding hopper on the carriage, said supply chute being connected to and fed from said holding hopper.
 15. A submarine traveler as in claim 1 wherein for each branch chute there is a sleeve, a sCreed comprising a wall structure telescopingly movably connected to said sleeve and an extension sleeve intermediate the sleeve and the branch chute, said extension sleeve having a length adapted to adjust the location of the outflow port relative to the diameter size of the pipe line.
 16. A submarine traveler as in claim 15 wherein an end edge of the extension sleeve is at an acute angle relative to the longitudinal axis of the sleeve whereby to locate the outflow port nearer to the center line of the pipe line.
 17. A submarine traveler as in claim 1 wherein there is a profile scanning device on the frame having a clear path of reference to the ballast after deposit and the pipe line adjacent thereto for sensing the finished profile of the ballast relative to the pipe. 